package com.dyrj.ysk.util;

import com.google.common.io.CharStreams;
import org.apache.commons.codec.Charsets;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

/**
 * 自定义访问对象工具类
 * 获取对象的IP地址等信息
 * @author 吴侠志  2019/8/31
 * @version 1.0
 */
public class CusAccessObjectUtil {
    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？
     * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
     * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130,
     * 192.168.1.100
     * 用户真实IP为： 192.168.1.110
     * @param request
     * @return
     */
    public static String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

    /**
     * 获取所有请求头部
     * @param request
     * @return
     */
    public static Map<String,String> getHeaders(HttpServletRequest request){
        Enumeration<String> headers= request.getHeaderNames();
        Map<String,String> res=new HashMap<>();
        while(headers.hasMoreElements()){
            String headerName = headers.nextElement();
            String headerValue=request.getHeader(headerName);
            res.put(headerName,headerValue);
        }
        return res;
    }
    //  获取请求参数
    public static Map<String,String> getAllRequestParam(HttpServletRequest request) throws IOException {
        Map<String, String> res = new HashMap<String, String>();
        Enumeration<?> temp = request.getParameterNames();
        if (null != temp) {
            while (temp.hasMoreElements()) {
                String en = (String) temp.nextElement();
                String value = request.getParameter(en);
                res.put(en, value);
                // 在报文上送时，如果字段的值为空，则不上送<下面的处理为在获取所有参数数据时，判断若值为空，则删除这个字段>
                if (res.get(en) == null || "".equals(res.get(en))) {
                    res.remove(en);
                }
            }
        }
        if(res.isEmpty()){
            String result = CharStreams.toString(new InputStreamReader(request.getInputStream(), Charsets.UTF_8));
            res= JsonUtil.jsonToPoJo(result,Map.class);
        }
        return res;
    }
}
